Wiring Through Corolla Firewall

I found a main harness grommet near the passenger side strut tower. Can be felt but not seen from inside when the glove box is out. Just got my wiring fished through there late yesterday. Project moving forward.

Thanks everybody!

If you look at the firewall, there are typically 1-3 spots that you can feed wire through. Often, around the wiring harness, or the steering column or even the brake booster, there will be a rubber boot sealing the unit to the firewall. I usually use a sharp wire, poke through the rubber and pull your wiring through. Once done, you can place some silicon around the puncture.

Will look into both options.

Thanks for the door post reminder. I actually just did that on our E450 coach cab when I had to run a new vacuum hose. Hadn't thought of it for the Corolla.

Will look at the door too.

I've gone with the main harness grommet on other vehicles, and when I recently did my Nissan pickup I used the A/C condensate drain grommet.

Thanks again, Case Pends...

there will be a spot where the main wiring harness enters the cabin. there should be enough room there to slip another wire through. that is where I brought the wiring through to communicate with the extra computer boxes I added to my pickup truck

just make sure you don't tear any rubber seals that the mfg put there to keep out weather, protect the edges of wires from sharp edges, etc

I had a similar question a while back, but for a PT Cruiser. Someone mentioned simply routing the wiring through the door opening and that is what I ended up doing because there didn't seem to be a good spot for drilling through the firewall. I brought the wires inside on the passenger side of the car. Under the hood, I used wire ties along with some sponge insulation to keep the wiring in place. There was a small gap in the metal where the hood met the fender, so that's where I tucked in the wire, holding it in place with the sponge rubber. I brought the wires inside near the bottom of the glove box and shoved the wiring behind the plastic molding where it meets the carpeting and then under the floor mat. I had just enough length in the break-away wires to reach the Brake Buddy. I ran the wiring inside the PT Cruiser in a similar fashion to the back end for the magnetic-mount tail lights. I still need to make a couple of steel brackets for the magnets to lock on to.

Before settling on this route, I figured it would be easier to drill from the exterior of the car into the interior as I would be less likely to hit something in the engine compartment.